Cold plates have long been used with beverage dispensers to chill fluids flowing therethrough. Generally described, a cold plate is an aluminum casting-type structure with a series of sleeves and/or tubes positioned or molded therein for fluid flow. The cold plate is generally positioned within the beverage dispenser in direct physical contact with an ice chest. The cold plate is generally positioned at the bottom of the ice chest. Fluids such as plain water, soda water, and syrup travel through the sleeves or the tubes within the cold plate. Heat is exchanged from the fluids through the sleeves or the tubes and the aluminum casting of the cold plate with the ice within the ice chest. The fluids are therefore chilled to the appropriate temperature before being served from the beverage dispenser.
An example of a known cold plate design is found in commonly-owned U.S. Pat. No. 5,319,947, entitled "Beverage Dispenser." The disclosure of this patent is incorporate herein by reference. The cold plate described in this example chills the fluids flowing therethrough in a conventional manner. Further, the cold plate also has an exterior sleeve connected thereto that extends outwardly so as to chill a conventional carbonator unit positioned somewhat below the cold plate. The carbonator unit mixes the incoming tap water with carbon dioxide gas so as to produce soda water. The exterior sleeve cools the carbonator unit by conduction such that the water within the carbonator unit is also chilled as it flows therethrough.
Although the extended carbonator sleeve described above provides for conduction cooling, temperature differences still may exist between the water in the carbonator unit and the fluids running through the cold plate itself. The effectiveness of the conduction cooling apparently may diminish somewhat given the distance between the ice chest and the carbonator unit. The ability to cool the carbonator unit to the same or at least to a similar temperature as the cold plate would increase the cooling efficiency of the beverage dispenser as a whole. What is needed, therefore, is a means for efficiently cooling the carbonator unit when used with a cold plate.